I'm not sure I follow. Isn't that a problem with any market where there's already a dominant player? You're saying that rather than coming up with a better solution, people should be thinking about better ways to get people to sign up?

  Why would I use this Facebook thing when MySpace works fine?
  Why would I use Reddit when Digg works fine?
  Why would I use OkCupid when Match.com works fine?
  Why would I use an iPhone when my Blackberry works fine?